Background Flashcards
What is the incidence of laryngeal cancer (LCX) in the United States?
∼12,000 cases/yr of LCX (∼20% of all H&N)
What are the risk factors for developing LCX?
Smoking, alcohol use, and voice abuse
What are the subsites of the larynx?
Supraglottic, glottic, and subglottic
What is the incidence/distribution of LCX according to subsite?
Glottic: 69%
Supraglottic: 30%
Subglottic: 1%
What % of premalignant lesions (leukoplakia/erythroplakia) progress to invasive laryngeal lesions?
20% of premalignant laryngeal lesions ultimately progress to invasive cancer (higher for erythroplakia than leukoplakia).
What is the most common LCX histology?
Squamous cell carcinoma (SCC) makes up >95% of LCX. Other histologies include verrucous carcinoma (1%–2%), adenocarcinoma, lymphoma, chondrosarcoma, melanoma, carcinoid tumor, and adenoid cystic carcinoma.
What are the subdivisions of the supraglottic larynx?
Supraglottic larynx: Epiglottis (suprahyoid and infrahyoid), AE folds, arytenoids, ventricles, and false vocal cords (FVCs)
What are the subdivisions of the glottic larynx?
Subglottis: 0.5 cm below the TVCs to the 1st tracheal ring
What are the nodal drainage pathways of the various laryngeal subsites?
Supraglottic: levels II–IV
Glottic: virtually no drainage
Subglottic: pretracheal and Delphian (level VI)
What is the incidence of hypopharyngeal cancer (HPxC) in the United States?
There are ∼2,500 cases/yr.
What is the median age at Dx for HPxC?
The median age at Dx is 60–65 yrs for HPxC.
What are the subsites of the hypopharynx (HPX)?
Pyriform sinus
Postcricoid area
Posterior pharyngeal wall
(Mnemonic: “3 Ps”)
What are the anatomic boundaries of the HPX?
The HPX spans from C4–6 or from the hyoid bone to the inf edge of the cricoid cartilage.
What is the sex predilection for HPxC based on the different subsites?
The sex predilection is predominantly male for pyriform sinus and post pharynx primaries, but predominantly female for postcricoid area tumors.
What are the classic risk factors for the development of HPxC?
Smoking, alcohol, betel nut consumption, nutritional deficiency (vitamin C, Fe [Fe deficiency is associated with 70% of postcricoid cancers in northern European women]), and prior Hx of H&N cancer
Is nodal involvement common with HPxC?
Yes. Nodal involvement is common due to abundant submucosal lymphatic plexus drainage to the retropharyngeal nodes, cervical LNs, paratracheal LNs, paraesophageal nodes, and SCV nodes.
What are the most commonly involved nodal stations in HPxC?
Levels II, III, and the retropharyngeal nodes are most commonly involved in HPxC. Level VI can also be involved and therefore should be covered when planning these cases for RT.
What is the name for the most sup of the lat retropharyngeal nodes?
The most sup of the lat retropharyngeal nodes is the Node of Rouviere.
What % of HPxC pts have nodal involvement at Dx?
∼75% overall have nodal involvement at Dx (∼60% for T1).
What is the typical histology seen in HPxC?
The predominant histology is SCC (>95%) → adenoid cystic, lymphoma, and sarcoma.
What are the most common subsites of origin for HPxC?
The pyriform sinus (70%–80%), post pharyngeal wall (15%–20%), and postcricoid (5%) are the most common subsites of origin.
At what cervical spine levels are the hyoid bone and the TVCs located?
The hyoid bone is at C3, whereas the TVCs are located near C5–6.
The subglottic space extends from
the first tracheal ring to
5 mm inferior to the free edge true vocal cords (TVCs)
The glottic larynx contains
the true vocal folds, anterior
commissure, posterior commissure, and the infraglottic
space (5 mm inferior to the free edge of the TVCs)
The supraglottic larynx contains
: ventricles, false vocal folds (FVCs), aryepiglottic folds, and epiglottis (infrahyoid, suprahyoid,
laryngeal surface, lingual surface).
medialized fixed cord is caused by
recurrent laryngeal
nerve injury
a lateralized fixed cord or hypomobile is
caused by
injury of intrinsic laryngeal muscles.
Lateralized fixed/hypomobile TVCs are often seen with
laryngeal cancer.
pre-epiglottic space is
anterior to the epiglottis and superior to the vocal
folds. It is contiguous with the paraglottic space and base of tongue. bounded by the mucosal surface
of the vallecula superiorly, hyoid/thyroid strap muscles
anteriorly, and root of the epiglottis posteriorly and inferiorly communicates with the paraglottic spaces.
The paraglottic space is
a small fat
plane adjacent to the thryoid cartilage. The paraglottic and pre-epiglottic spaces are connected
fat planes. The paraglottic space is bounded by the thyroid cartilage laterally and the TVCs, FVCs medially. Laryngeal cancer often invades the paraglottic and preepiglottic spaces. There are no barriers to spread to the
adjacent space if one is involved
FVCs can be distinguished
from the TVCs because
FVCs have a band of fatty tissue and the
TVCs do not
